Tennis star Serena Williams, who is friends with Meghan, could still technically be one of Archie's godparents, despite not being at the christening, according to a royal expert (Picture: TOBY MELVILLE/AFP/Getty Images)

He told Yahoo UK’s ‘The Royal Box’ that he had done some research and she could still technically be one of Archie’s godparents despite not being there on the day.

He said: “I actually looked into some of the rules here, ‘can you be a godparent and not attend the christening?’, and as long as someone attended on her behalf she still could be a godparent.

Serena, 37, was asked if she had been was asked if she had been asked to be Archie’s godmother, during a press conference and replied: “No, I’m working on Saturday… so, she understands work”.

The seven-time Wimbledon champion is also a Jehovah’s Witness, which could make it hard to be a godparent to a royal baby anyway.

Church of England rules dictate that godparents themselves must first be baptised before they can take on the role - something Serena hasn’t as a Jehovah’s Witness.

Jehovah’s Witnesses are also apparently urged not to attend wedding ceremonies for people of a different religion, though Williams and her husband Alexis Ohanian were guests at Meghan and Harry’s wedding last year.

Meghan made a surprise visit to Wimbledon to watch friend Serena Williams play (Picture: AP)

The pair, who are believed to have struck up a friendship at the Super Bowl in 2010, have supported each other over the years, with Meghan cheering Serena on in various tennis tournaments and the sportswoman reportedly organising Meghan’s baby shower in New York earlier this year.